Firefighters exposed to the World Trade Center attacks are more likely to get cancer, while 9/11 rescue workers still suffer high illness rates generally, according to studies published Friday.
In a 10th anniversary edition of medical journal The Lancet, scientists said however that death rates among emergency staff and civilians who survived the disaster were lower than those of the wider New York City population.
"The events of that day changed the historical trajectory of America and the world. They have had -- and continue to have -- profound consequences for health," the Lancet journal said in an editorial.
One study showed that New York City firefighters who rushed to the doomed Twin Towers a decade ago are 19 per cent more likely to have cancer than their non-exposed colleagues and a comparable section of the city's population.
There were 263 cancer cases in the exposed firefighters compared with 238 expected from general population data, while from the non-exposed group there were only 135 compared with 161 expected from the general population.
The study, led by David Prezant, chief medical officer of the Fire Department of the City of New York (FDNY), and colleagues, looked at 9,853 male firefighters with health records dating back to well before 9/11.
Another study in the Lancet showed a high burden of both physical and mental illness in the estimated 50,000 rescue and recovery workers involved in the September 11, 2001 attacks on New York by Al-Qaeda.
Data gathered from more than 27,000 of those workers, who enrolled in a federally funded monitoring programme, showed that 28 percent had developed asthma, 42 percent sinusitis, and 39 percent gastrooesophageal reflux disease.
Twenty-eight per cent had depression, 32 per cent had post traumatic stress disorder and 21 per cent had panic disorder, said the study by Juan Wisnivesky, of the Mount Sinai School of Medicine in New York state.
"Our findings show a substantial burden of persistent physical and mental disorders in rescue and recovery workers who rushed to the site of the WTC and laboured there for weeks and months 10 years ago," the study said.
But World Trade Center-exposed rescue workers and civilians have had lower death rates than New York City general population, a third study by researchers at the New York City Department of Health and Mental Hygiene.
They said the fact that most of those exposed were employed and that they had volunteered for the study -- both employed people and study volunteers are largely healthier than the overall population -- could account for the result.